The invention relates to independent storage device management, and more particularly, to data migration systems and methods for independent storage device expansion and adaptation.
Redundant array of independent disks (RAID) is a disk subsystem used to increase performance, provide fault tolerance, or both. RAID is equipped with two or more ordinary hard disks and a RAID disk controller. Performance is improved by disk striping, which interleaves bytes or groups of bytes across multiple drives, thus, reading and writing of more than one disk can occur simultaneously. Fault tolerance is achieved by mirroring or disk striping with parity. Mirroring is full duplication of data on two drives. In disk striping with parity, parity is used to calculate the actual data in two drives and store the results on a third drive. After a failed drive is replaced, the disk controller automatically rebuilds the lost data from two remaining drives.
RAID expansion and adaptation, however, requires excessive data migration. Thus, data migration systems and methods for RAID expansion and adaptation capable of reducing migration time, and preventing data loss due to errors are desirable.